Inflatable restraint systems have previously been used, and are intended for protecting an occupant of a vehicle against injury by physically restraining the occupant's body when the vehicle encounters a collision. Traditionally, inflatable restraint systems for use in automobiles have generally consisted of structural components and gas generant for instantaneously generating gas to inflate an inflatable airbag cushion. The gas generant is ignited by an ignitor connected to a remote deceleration sensor. One or more filters and a gas diffuser are also normally located between the gas generant and the airbag cushion.
Most current inflatable restraint systems comprise a number of separate components including a base plate, an inflator assembly, filter chambers, a diffuser, an inflatable airbag and an airbag retainer. These separate components are used in the systems shown and described in U.S. Pat. Nos. 5,201,542, 4,830,401 and 3,984,126. The inflator assembly contains the gas generant and ignitor, and generates the gas for inflating the airbag. One of the filter chambers normally holds an arrangement of metallic wire mesh and non-metallic fibers that absorbs heat from the generated gas and inhibits or prevents solid particles from passing through the filter chamber. The other filter chamber normally contains a screen material for preventing solid particles from entering the airbag cushion, while the diffuser meters and distributes the generated gas into the airbag.
Combining two or more of the filter chambers, a diffuser and a retainer ring into a integral unit would reduce manufacturing time, and the complexity and cost of an inflatable restraint system.